Single-piece heat exchanger

ABSTRACT

A heat exchanger is provided with a unitary, single-piece structure that can be formed via 3D printing, for example. The heat exchanger includes a main body defining a first fluid inlet port, a first fluid outlet port, a second fluid inlet port, and a second fluid outlet port, wherein each of these fluid ports are integrally formed with the main body. A plurality of plates are stacked and integrally formed with the body. First fluid channels are defined by gaps in the material of the main body and are in fluid communication with the first fluid inlet port. Second fluid channels are defined by gaps in the material of the main body and are in fluid communication with the second fluid inlet port. The first fluid channels and the second fluid channels are interposed between the plates in alternating fashion along the stacked arrangement.

CROSS REFERENCE TO RELATED APPLICATIONS

The present patent application claims the benefit of the following U.S.Provisional Patent Applications: U.S. Provisional Patent Application No.62/881015, filed Jul. 31, 2019; U.S. Provisional Patent Application No.62/884922, filed Aug. 9, 2019; U.S. Provisional Patent Application No.62/887852, filed Aug. 16, 2019; U.S. Provisional Patent Application No.62/887866, filed Aug. 16, 2019; and U.S. Provisional Patent ApplicationNo. 62/887886, filed Aug. 16, 2019. The above applications areincorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to a heat exchanger, and moreparticularly to a chiller heat exchanger with a unitary body definingvarious fluid flow ports and flow paths.

BACKGROUND

Plate-type heat exchangers are used to transfer thermal energy betweenheat exchange working fluids. At least two heat exchange working fluidstreams flow through separate flow passages defined between heatexchanger plates in the plate-type heat exchanger. Usually, the heatexchanger plates are arranged in a stacked relation, forming a part ofthe plate-type heat exchanger. The separate flow passages are defined byports formed in the heat exchanger plates and flow channels formedbetween the heat exchanger plates.

Heat transfer between the working fluid streams can occur between twoadjacent plates. For example, a first working fluid stream flows in oneplate, and simultaneously a second working fluid stream flows in anadjacent plate of the stack. Thus, heat is exchanged between the twoworking fluid streams flowing through the stacked plates of the heatexchanger.

One type of plate-type heat exchanger is a chiller heat exchanger, whichtypically is used to cool the working fluids flowing through the chillerheat exchanger from a heat source such as an engine, a motor, or abattery of a vehicle, for example.

SUMMARY

In one embodiment, a heat exchanger includes a main body defining afirst fluid inlet port, a first fluid outlet port, a second fluid inletport, and a second fluid outlet port, wherein each of the first andsecond fluid inlet ports and first and second fluid outlet ports areintegrally formed with the main body. A plurality of plates are in astacked arrangement and integrally formed with the main body. Aplurality of first fluid channels are defined by the main body and arein fluid communication with the first fluid inlet port to receive afirst fluid therefrom. A plurality of second fluid channels are definedby the main body and are in fluid communication with the second fluidinlet port to receive a second fluid therefrom. The first fluid channelsand the second fluid channels are interposed between the plates inalternating fashion along the stacked arrangement.

In another embodiment, a heat exchanger includes a main body defining afirst fluid inlet port, a first fluid outlet port, a second fluid inletport, and a second fluid outlet port, wherein each of the first andsecond fluid inlet ports and first and second fluid outlet ports areintegrally formed with the main body. A plurality of plates are in astacked arrangement and integrally formed with the main body, theplurality of plates defining fluid channels therebetween, the pluralityof plates including an upper-most plate. A plurality of manifolds areintegrally formed with the main body. The plurality of manifolds includea first inlet manifold configured to receive a first fluid from thefirst fluid inlet port, a first outlet manifold configured to send thefirst fluid to the first fluid outlet port, wherein the first outletmanifold is located on an opposite side of the heat exchanger from thefirst inlet manifold, a second inlet manifold configured to receive asecond fluid from the second fluid inlet port, and a second outletmanifold configured to send the second fluid to the second fluid outletport, wherein the second outlet manifold is located on an opposite sideof the heat exchanger from the second inlet manifold. A jumper pipe isintegrally formed with the main body, wherein the jumper pipe extendsacross the upper-most plate and transfers the first fluid from the firstfluid inlet port to the first inlet manifold.

In another embodiment, a 3D-printed chiller heat exchanger includes amain body of a single continuous solid material defining: a plurality ofplates arranged in a stack and formed as part of a single unitary body;a plurality of first fluid channels and a plurality of second fluidchannels interposed between the plates in alternating fashion such thateach of the first fluid channels is directly adjacent to a respectiveone of the second fluid channels and separated by a respective one ofthe plates; a first inlet manifold and a first outlet manifold in fluidcommunication with the plurality of first fluid channels; a second inletmanifold and a second outlet manifold in fluid communication with theplurality of second fluid channels; a first fluid inlet port and a firstfluid outlet port configured to allow a first fluid to enter and exitthe heat exchanger, the first fluid inlet port and first fluid outletport in fluid communication with the first fluid channels; a secondfluid inlet port and a second fluid outlet port configured to allow asecond fluid to enter and exit the heat exchanger, the second fluidinlet port and second fluid outlet port in fluid communication with thesecond fluid channels; and a jumper pipe fluidly connecting the firstfluid inlet port to the first inlet manifold.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a top perspective view of a heat exchanger accordingto one embodiment.

FIG. 2 illustrates a cross-sectional view taken along line A-A of FIG.1, according to one embodiment.

FIG. 3A illustrates a top schematic plan view of one fluid channel ofthe heat exchanger for a first type of fluid (e.g., refrigerant),according to one embodiment.

FIG. 3B illustrates a top schematic plan view of another fluid channelof the heat exchanger for a second type of fluid (e.g., coolant),according to one embodiment.

FIG. 4 illustrates a plot of a fluid path length versus a fluid channelposition, according to one embodiment.

FIG. 5 illustrates a cross-sectional view taken along line A-A of FIG.1, according to another embodiment.

FIG. 6 illustrates a similar cross-sectional view of another heatexchanger, according to another embodiment.

FIG. 7 illustrates a heat map of a fluid channel of FIG. 3A, accordingto one embodiment.

FIG. 8A illustrates a cross-sectional view of a heat exchanger having amanifold according to a first embodiment.

FIG. 8B illustrates a cross-sectional view of a heat exchanger having amanifold according to a second embodiment.

FIG. 8C illustrates a cross-sectional view of a heat exchanger having amanifold according to a third embodiment.

FIG. 9A illustrates a heat map of a fluid channel, and FIG. 9Billustrates the fluid channel with a manifold shape to control flowdistribution, according to one embodiment.

FIG. 10 illustrates one embodiment of an interior of a fluid manifold ofa heat exchanger.

FIG. 11 illustrates another embodiment of an interior of a fluidmanifold of a heat exchanger.

FIG. 12 illustrates a top plan view of a body (e.g., top plate) of aheat exchanger with a jumper pipe according to one embodiment.

FIG. 13 illustrates a cross-sectional view along line B-B of FIG. 12,according to one embodiment.

FIG. 14 illustrates a top plan view of a body (e.g., top plate) of aheat exchanger with a jumper pipe according to another embodiment.

FIG. 15A illustrates a top plan view of a fluid channel of a heatexchanger with an arrow indicating a twist.

FIG. 15B illustrates a top perspective view of a heat exchanger with atwisted flow path, according to one embodiment.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It is to beunderstood, however, that the disclosed embodiments are merely examplesand other embodiments may take various and alternative forms. Thefigures are not necessarily to scale; some features could be exaggeratedor minimized to show details of particular components. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a representative basis forteaching one skilled in the art to variously employ the embodiments. Asthose of ordinary skill in the art will understand, various featuresillustrated and described with reference to any one of the figures maybe combined with features illustrated in one or more other figures toproduce embodiments that are not explicitly illustrated or described.The combinations of features illustrated provide representativeembodiments for typical applications. Various combinations andmodifications of the features consistent with the teachings of thisdisclosure, however, could be desired for particular applications orimplementations.

FIG. 1 illustrates a heat exchanger 20 according to one embodiment ofthe present disclosure. In one embodiment, the illustrated heatexchanger 20 is a chiller heat exchanger used to cool a traction batteryfor a battery-powered (or hybrid) automotive vehicle, with workingfluids flowing through the chiller heat exchanger from a heat source(e.g., the battery). The teachings provided herein are not limited toonly this type of heat exchanger. Rather, the heat exchanger can be oneconfigured to use to cool an automotive engine, a motor, or other suchheat source. And, the teachings provided herein can be applied in othernon-automotive settings, such as commercial, residential, marine,aeronautical, and the like. In short, the heat exchanger 20 and othersshown herein are merely exemplary, and the term “heat exchanger” shouldnot be limited to only a chiller heat exchanger or just the typeillustrated in the Figures.

The heat exchanger may include a main body 22. The main body 22 maydefine an outer shell, or housing of the heat exchanger 20. The mainbody 22 can be formed as a single, unitary piece, via, for example,three-dimensional (3D) printing. The material used to form the main body22 can be metal, such as aluminum. In one embodiment of 3D printing, thepart begins as a powder (e.g., metal such as aluminum) that can be laiddown in thin layers that are melted and re-solidified only in the areasthat will make up the final part. Various intricate flow chambers,passages, inlets, outlets, inlet manifolds and outlet manifolds (all ofwhich are described below) can be defined by openings or gaps in themain body 22 (e.g., locations in which melting and solidifying of themetal does not take plate). The entire structure shown in the variousFigures, such as FIGS. 1-2, may be an integrally formed, unitary piece.In other words, the single, integrally formed, unitary nature of themain body 22 of the heat exchanger 20 allows for heat to be exchangedwithin the main body 22 without the use of individually or separatelyconnected plates. Indeed, as will be described below, the “plates” canbe formed out of the main body 22 itself. This integrally formed natureof the heat exchanger 20 allows for various components described hereinto have structural properties that were not possible with previousassembled heat exchangers.

The main body 22 has a general profile or shape that is oblong orfootball-shaped, having two elongated walls 24 meeting at correspondingnarrow ends 25. At an upper portion of the heat exchanger 20 are aplurality of ports that can be formed or defined by the material of themain body 22 itself. These ports can include first and second inletports, and first and second outlet ports. In particular, these ports caninclude a first inlet port 26 defining a first inlet to the heatexchanger 20 and fluidly coupled to a first fluid outlet port 28defining a first outlet of the heat exchanger 20. The ports can alsoinclude a second fluid inlet port 30 defining a second inlet to the heatexchanger 20 and fluidly coupled to a second fluid outlet port 32defining a second outlet of the heat exchanger 20. The first inlet port26 can be configured to connect to a supply of a first fluid, while thesecond fluid inlet port 30 can be configured to connect to a supply of asecond fluid. Each of the ports may be defined by a projection extendingoutward form the main body 22 that has a hollow interior defining therespective inlet or outlet. During a heat exchange process, as will bedescribed further herein, the first fluid can flow from the first inletport 28 to the first fluid outlet port 28, and the second fluid can flowfrom the second fluid inlet port 30 to the second fluid outlet port 32.The first and second fluids can remain fluidly isolated by the materialof the main body 22; passing the fluids across one another whileseparated by material of the main body 22 can exchange heat between thepassing first and second fluids.

Although many different fluids may be used in a heat exchange process,in one embodiment the first fluid is a refrigerant (e.g.,Hydrofluorocarbon (HFC), R-134, etc.) and the second fluid is a coolant(e.g., water, ethyl glycol, diethylene glycol, or propylene glycol,betaine, polyalkylene glycol, etc.) These working fluids are merelyexamples, and in other embodiments one or more of the fluids is orcontains engine oil (if the heat exchanger is used to cool an engine),transmission oil (if the heat exchanger is used to cool a transmission),power-steering fluid (if the heat exchanger is used to cool apower-steering unit), and the like. In the illustrated embodiment anddescribed herein, the heat exchanger 20 is a refrigerant-to-liquid heatexchanger as part of a battery cooling system for a battery of anautomotive vehicle. However, in other embodiments, the heat exchangercan be a utilized or referred to as a liquid-to-liquid heat exchanger,refrigerant-to-coolant heat exchanger, oil-to-coolant heat exchanger,oil-to-refrigerant heat exchanger, etc.

FIG. 2 is a cross-sectional view of the heat exchanger 20, taken alongline A-A of FIG. 1. Referring to FIGS. 1-2, the main body 22 of the heatexchanger 20 can have a plurality of fluid channels (also referred to asflow channels, fluid passages fluid passages, etc.) defined therein bygaps or openings in the solid material of the main body 22. For example,the main body 22 may define a plurality of first fluid channels 36configured to transport the first fluid, and a plurality of second fluidchannels 38 configured to transport the second fluid. The fluid channelsare stacked in alternating fashion, such that each of the first fluidchannels 36 are vertically adjacent to one or two of the second fluidchannels 38, and vice versa. FIG. 3A is a top view of one of the firstfluid channels of the stack, and FIG. 3B is a top view of one of thesecond fluid channels 38 of the stack. FIG. 1 shows the stack of fluidchannels 36, 38 in broken lines to schematically illustrate theirposition relative to the main body 22 of the heat exchanger 20.

Referring to FIGS. 1-3, the main body 22 of the heat exchanger 20 isalso formed to define a plurality of manifolds. For example, the mainbody 22 may define a first inlet manifold 40, a first outlet manifold42, a second inlet manifold 44, and a second outlet manifold 46. Thefirst inlet manifold 40 permits the first fluid to flow into (enter) thefirst fluid channels 36, and the first outlet manifold 42 permits thefirst fluid to flow out of (exit) the first fluid channels 36. Likewise,the second inlet manifold 44 permits the second fluid to flow into thesecond fluid channels 38, and the second outlet manifold 46 permits thesecond fluid to flow from the second fluid channels 38. The first inletport 26 is in fluid communication with the first inlet manifold 40 topermit the first fluid to flow into the heat exchanger 20, and the firstfluid outlet port 28 is in fluid communication with the first outletmanifold 42 to permit the first fluid to flow out of the heat exchanger20. Likewise, the second fluid inlet port 30 is in fluid communicationwith the second inlet manifold 44 to permit the second fluid to flowinto the heat exchanger 20, and the second fluid outlet port 32 is influid communication with the second outlet manifold 46 to permit thesecond fluid to flow out of the heat exchanger 20.

The manifolds 40-46 extend vertically within the heat exchanger 20,fluidly connecting multiple fluid channels. For example, the first inletmanifold 40 and the first outlet manifold 42 each fluidly couple thestacked first fluid channels 36; the second inlet manifold 44 and thesecond outlet manifold 46 each fluidly couple the stacked second fluidchannels 38. During operation, the first fluid entering the heatexchanger 20 via the first inlet port 26 flows downward through thefirst inlet manifold 40 whereupon the fluid can separate to enter thevarious first fluid channels 36. Then, the fluid travels horizontallythrough the first fluid channels 36 and recombines in the first outletmanifold 42, whereupon the first fluid can flow vertically upward andexit the first fluid outlet port 28. The second fluid can flow similarlythrough the second manifolds 44, 46, second fluid channels 38, andsecond inlet and outlet ports 30, 32.

The flow of the first fluid and the second fluid through the respectivefirst fluid channels 36 and second fluid channels 38 is in a curvedmanner. For example, in the first fluid channel 36 shown in FIG. 3A, thefluid flows from a first quadrant to a third quadrant of the heatexchanger 20, and in a curved (e.g., non-linear) fashion. This flow pathis represented by arrow 48. In the second fluid channel 38 shown in FIG.3B, the fluid flows from a second quadrant to a fourth quadrant of theheat exchanger 20. This flow path is represented by arrow 50.

To further facilitate these flow paths, a first plurality of fins 52 areformed in the first fluid channel 36, and a second plurality of fins 54are formed in the second fluid channel 38. The fins 52, 54 may be formedas part of the single, unitary main body 22 of the heat exchanger 20via, e.g., 3D printing. The fins 52, 54 follow the general shape of therespective flow paths 48, 50 to direct the flow in that shaped path fromthe inlet manifold to the outlet manifold associated with each fluidchannel. The fins 52, 54 may extend vertically from one or both of theupper and lower portions of the fluid channels 36, 38. In other words,the fins 52, 54 may extend partially into (or fully through) the fluidchannels 36, 38 in the vertical direction. The fins 52, 54 may be moregenerally referred to as guides, and may have other shape or structurenecessary to guide or influence the fluid in a certain direction.

Thicker, more pronounced fins may also be provided as structuralreinforcement. For example, FIG. 3A illustrates two enlarged fins 56following the general shape of the flow path 48, and FIG. 3B illustratestwo enlarged fins 58 following the general shape of the flow path 50.These enlarged fins 56, 58 are wider than the smaller fins 52, 54 in therespective fluid channels 36, 38. These enlarged fins 56, 58 can extendvertically entirely through their respective fluid channel 36, 38. Thisis shown in FIG. 2, for example, in which the material of the main body22 is shown to extend entirely vertically through the stack of fluidchannels, representing the location of the enlarged fins 56 in the firstfluid channel 36 in the cross-section. The fins 56, 58 providestructural reinforcement to the vertical stack of fluid channels. Inother words, the fins 56, 58 may help support the material of the mainbody 22 that is directly above that fluid channel.

As mentioned above, the material of the main body 22 can itself definethe fluid channels 36, 38. It can therefore be said that the material ofthe main body 22 can define “plates” of solid material verticallyseparating the stack of fluid channels 36, 38. For example, as shown inFIG. 2, a plurality of plates 60 may be located adjacent to respectivefluid channels 36, 38. Each plate 60 may be interposed between twoadjacent fluid channels. In one embodiment, a plurality of the plates 60may each be interposed between a first fluid channel 36 and a secondfluid channel 38, so that the first fluid channels 36 and second fluidchannels 38 are stacked in alternating flow directions. With the abilityto form the heat exchanger 20 via 3D printing, for example, the materialof each plate 60 can be unitary and solid with the material of the otherplates 60. This matter of formation (e.g., 3D printing) allows for theability to design the heat exchanger 20 with more intricacy andprecision, enabling precisely controlled flow patterns and packagingshapes, as well as the precise and detailed shape of smaller detailssuch as the fins 52, 54.

Using the intricate forming methods such as 3D printing, a “hybridcounter cross flow” of fluid is enabled. For example, referring to FIGS.3A-3B, the fins 52 of the first fluid channels 36 direct the first fluidin an S-shape, from the first input manifold 40 in the first quadrant tothe first output manifold 42 in the third quadrant, as indicated byarrows 48. Meanwhile, the fins 54 of the second fluid channels 38 directthe second fluid in an S-shape mirrored to that of the first fluidchannels 36, with the fluid flowing from the second input manifold 44 inthe second quadrant to the second output manifold 46 in the fourthquadrant, as indicated by arrows 50. Likewise, the first inlet manifold40 can be located in the first quadrant, diagonally across the heatexchanger 20 from the first outlet manifold 42 which is located in thethird quadrant. And, the second inlet manifold 44 can be located in thesecond quadrant, diagonally across the heat exchanger 20 from the secondoutlet manifold 46. This creates a “cross” flow direction, with thefirst fluid flowing in a direction that crosses the second fluid invertically-overlapping fluid channels 36, 38.

The first fluid channel 36 has a central region 64 of linear fluid flow,and the second fluid channel 38 has a corresponding central region 66 oflinear fluid flow. These two central regions 64, 66 vertically overlapeach other in the stacked arrangement described above. Therefore, asshown by the flow arrows 48 and 50 the first fluid flows directlycounter to the second fluid within the two central regions 64, 66. Thiscreates a “counter” flow of fluid, with the first fluid flowinggenerally 180 degrees (e.g., “counter”) to the second fluid. Combiningboth the counter flow and the cross flow described above creates ahybrid counter cross flow profile, which provides optimum heat transferthrough the heat exchanger 20.

The fins or guides 52, 54 can force the fluid to flow along arrows 48 inthis “hybrid counter cross flow” path. For example, within the centralregions 64, 66 of the stacked arrangement, the first fluid flowsopposite or “counter” to the second fluid. In other words, a centralregion 64 of the first fluid channel has a flow direction that isopposite to a corresponding or overlapping central region 66 of thesecond fluid channel. Outside of the central regions 64, 66, the firstfluid flows in a “cross” direction angled relative to the second fluid.In other words, in a region outside of the central region 64 of thefirst fluid channel, the flow direction of the first fluid is crossrelative to an overlapping region of the second fluid channel. The“cross” direction can mean perpendicular, oblique, or transverse (e.g.,laying across but not necessarily perpendicular), or the like.

Referring to FIGS. 1-2, the heat exchanger 20 can also be provided witha jumper pipe 62. Like other structure of the heat exchanger 20, thejumper pipe 62 may be formed via the same method (e.g., 3D printing) aspart of the unitary, single-piece design. The jumper pipe 62 is locatedabove the upper-most plate 61 of the stack of plates 60 such that thejumper pipe is vertically isolated above the fluid channels 36, 38 inwhich the hybrid counter cross flow heat exchange occurs. The jumperpipe 62 is a fluid channel or tube configured to carry the first fluid(e.g., refrigerant) from the first inlet port 26 and across the mainbody 22 before the first fluid is allowed to flow downward into thefirst inlet manifold 40 to access the stack of fluid channels 36. Duringthis process in which fluid flows through the jumper pipe 62, the fluiddirectly may contact the upper-most plate 61.

By providing such a jumper pipe 62, the first inlet port 26 and firstfluid outlet port 28 can be located adjacent to one another. The firstinlet port 26 and first fluid outlet port 28 may be integrally formed aspart of a common extrusion and configured to connect to a single fluidcoupling. This allows for a single fluid connector or connection with asource of fluid to be made, rather than requiring two separateconnection points (such as the second fluid inlet port 30 and secondfluid outlet port 32). Fluid can flow in and out of the heat exchangerat a single localized region of the heat exchanger 20, allowing thefirst inlet port 26 and first fluid outlet port 28 to connect to asingle unit carrying the first fluid. The dual region of the first inletport 26 and the first fluid outlet port 28 can be referred to as anintegrated block or mount. This enables an optimization of the locationof the integrated mount to improve the refrigerant flow through the heatexchanger, reducing pressure drops. No separate connection is requiredbetween the plates 60 and the integrated mount, and therefore theoverall size (e.g., height) of the heat exchanger 20 is reduced.

Moreover, by providing this jumper pipe 62 via 3D printing of the mainbody 22, the shape and design of the jumper pipe 62 can be intricatelydesigned to maximize efficient fluid flow. By doing this, the jumperpipe 62 can take up as little space as possible, allowing its length tobe reduced which, in turn, reduces fluid pressure drop across the jumperpipe 62. Additionally, integration of the jumper pipe 62 with the mainbody 22 in a singular unit allows the jumper pipe 62 and an upper-mostplate 61 to have heat transfer therebetween, due to the upper-most platealso being a lower boundary of the jumper pipe 62. This improvesperformance of the heat exchanger 20. Moreover, integration of thejumper pipe 62 removes a step of assembling a separate jumper pipe tothe heat exchanger, thus decreasing certain costs of manufacturing.

FIG. 4 is a graphical representation or a plot of a fluid path lengthversus a fluid channel position. Referring back to FIGS. 3A for example,between each pair of adjacent fins 52 is a miniature channel. Thestarting position of each channel is what is plotted on the X-axis ofthe graph of FIG. 4. In other words, as the X-axis increases, the graphis referring to the distance (e.g., millimeters, mm) of the position ofeach channel from a boundary wall 24 of the heat exchanger 20.Meanwhile, the Y-axis refers to the length of each channel. As can beseen by this relationship, the channels closest to the boundary walls 24of the heat exchanger 20 have the shortest flow path length, while thechannel in the center of the fluid channel 36 has the longest flow pathlength. In the illustrated embodiment, the range of flow path lengths isbetween approximately 123 mm and 143 mm, with an average ofapproximately 133 mm. And, the maximum channel position distance (e.g.,the curved length between the outer-most boundary channels) isapproximately 70 mm.

These measurements are one embodiment, and other ranges of measurementsmay be utilized depending on the flow and size requirements of the heatexchanger 20. For example, in another embodiment, the flow path lengthscan be between approximately 100 mm and 150 mm, and the maximum channelposition distance can be between approximately 50 mm and 100 mm.

FIG. 5 illustrates an embodiment in which the heat exchanger 20 includesa void or gap 70 between the jumper pipe 62 and the upper-most plate 61.It can also be said that the void or gap 70 is defined within theupper-most plate 61, between the jumper pipe 62 and the upper-most fluidchannel. The void or gap 70 may be an absence of material of the mainbody 22 of the heat exchanger. This void or gap 70 may be formed duringthe formation process of the main body 22 (e.g., 3D printing).Alternatively, this void or gap 70 may be formed after the formationprocess of the main body 22 by, for example, milling or drilling toremove this material.

This void or gap 70 may be provided in embodiments in which unwantedheat transfer happens between the jumper pipe 62 and the upper-mostplate 61. In embodiments in which such heat transfer is not desirable,the void or gap 70 helps to thermally insulate the fluid in the jumperpipe 62 from the fluid in the fluid channels 36, 38. The void or gap 70may be filled with air, for example.

In one embodiment, the void or gap 70 is fluidly coupled to apowder-evacuation hole 72. The powder-evacuation hole 72 can be formedduring the manufacturing of the main body 22 (e.g., 3D printing) toprovide as a pathway to evacuation the excess or residual power leftoverfrom the 3D printing of the material surrounding the void or gap 70. Thepowder-evacuation hole 72 can be open to the atmosphere at opening 74.During manufacturing, an operator may insert tool (such as a vacuum orair-pressure source) through the opening 74 and into thepowder-evacuation hole 72, whereupon activation of the tool can forcethe residual powder to evacuate the void or gap 70 through thepowder-evacuation hole 72. In the illustrated embodiment, the void orgap 70 runs in a direction parallel to the length of the fluid channels36, 38, and the powder-evacuation hole 72 extends transverse (e.g.,perpendicular) to the void or gap 70. The powder-evacuation hole 72 canextend in a space between the first inlet port 26 and first fluid outletport 28, for example. The powder-evacuation hole 72 can be capped orotherwise sealed after the powder from the 3D printing is removed fromthe void or gap 70.

FIG. 6 shows another embodiment of a heat exchanger 80. In the interestof brevity, the heat exchanger 80 includes all of the basic features ofthe heat exchanger 20, unless otherwise described below. In thisembodiment, the heat exchanger 80 includes a larger stack of plates 82than the previous embodiment, and therefore a larger stack of firstfluid channels 84 and second fluid channels 86. Any number of plates 82and first fluid channels 84 and second fluid channels 86 may be used,depending on vehicle packaging requirements. In this embodiment, eight(8) first fluid channels 84 are utilized, and seven (7) second fluidchannels are utilized. Moreover, in this embodiment, the plates 82 canhave varying thicknesses. For example, a bottom-most plate 88, whichdirectly borders one of the first fluid channels 84, can be thicker thanthe other plates 82 that are located vertically between a pair of fluidchannels 84, 86.

FIG. 7 illustrates a heat map or thermal image of a fluid channel, suchas the first fluid channel 36 illustrated in FIG. 3A, according to oneembodiment. As shown in this view, the first fluid (e.g., refrigerant)is flowing in the direction of arrow 48, as explained with reference toFIG. 3A. The darker shaded regions indicate a lower fluid temperature,and the lighter regions indicate a higher fluid temperature. As can beseen in FIG. 7, there may be a “dry out region”. This region shows apresence of uneven heat transfer (e.g., an uneven amount of heat beingremoved from the refrigerant). This is indicated by the lighter colorcreeping into this dry out region. This uneven heat transfer can disruptfluid flow within the first fluid channel 36.

FIGS. 8A-8C provide three different heat exchanger bodies that areprovided to combat the problems with the uneven heat transfer explainedwith reference to FIG. 7. As will be explained, the heat transferdistribution can be controlled by modifying an angle of one or more ofthe walls of the manifolds in which the fluid collects.

For example, FIG. 8A illustrates a heat exchanger 90 according to oneembodiment. The heat exchanger 90 may include the structure orcharacteristics of the heat exchangers explained in previousembodiments, unless otherwise stated. Similar to embodiments above, theheat exchanger 90 may have a main body 92 formed via, e.g., 3D printing.This manufacturing method allows a stack of fluid channels, such asfirst fluid channels 94 and second fluid channels 96, to be formed byvoids in the material of the main body 92. The first fluid channels 94can receive a first fluid from a first inlet manifold 98 and transfer itto a first outlet manifold (not shown), while the second fluid channels96 can receive a second fluid from a second inlet manifold 100 andtransfer it to a second outlet manifold (not shown). Each manifold maybe defined by the material of the unitary structure of the main body 92.For example, the second inlet manifold 100 may be defined in part by alower floor 102 and an outer wall 104. An angle is defined between thelower floor 102 and the outer wall 104. As shown in the embodiment inFIG. 8A, this angle may be 91 degrees or generally perpendicular.

Changing this angle can impact the flow characteristics of the fluidflowing into or out of the fluid channels to normalize the heat exchangedistribution. For example, FIG. 8B shows a similar heat exchanger 90′having similar structure as the heat exchanger 90 of FIG. 8A, except fora larger angle between its lower floor 102′ and an outer wall 104′. Inthis embodiment, the angle between the lower floor 102′ and the outerwall 104′ is 105 degrees. This effectively narrows the interior volumeof the second inlet manifold 100′ at a lower portion thereof to restrictflow of the second fluid in that portion of the second inlet manifold100′. This does not increase the pressure of the second fluid, butrather decreases the flow rate of the second fluid in thisreduced-volume area of the manifold, which correspondingly increases thefluid flow in other regions of the heat exchanger. Adjusting the angleor interior volume of the manifold during manufacturing (e.g., 3Dprinting) can tune the heat exchange process throughout the heatexchanger to account for potential abnormalities in the heat exchangedistribution.

FIG. 8C illustrates another embodiment with an increased angle between alower floor and outer wall of a manifold. In particular, the heatexchanger 90″ has a second inlet manifold 100″ defined by a lower floor102″ and an outer wall 104″. The angle at the intersection of the lowerfloor 102″ and the outer wall 104″ in this embodiment is 115 degrees.This can even further reduce the volume within the second inlet manifold100″ in the lower region thereof, which can again restrict fluid flow inthat region, and increase fluid flow in another region of the heatexchanger 90″.

While the embodiments described above regarding FIGS. 8A-8C explainadjustment of an angle of a second inlet manifold 100, 100′ 100″, itshould be understood that this sort of manipulation of shape and volumecan be applied to any of the manifolds of the heat exchanger. Forexample, any or all of the first or second inlet manifolds or first orsecond outlet manifolds can have similar adjustments to their interiorvolume and angle of intersection between a floor and an outer wall.

Moreover, the precise angles described in FIGS. 8A-8C of 91 degrees, 105degrees, and 115 degrees are merely exemplary. Other ranges of anglescan be utilized. And of course, to combat certain heat exchangeabnormalities, it may be necessary to reduce the angle to less than 90degrees, for example 80 degrees, to effectively increase the interiorvolume of the manifold in the lower region thereof.

FIG. 9 illustrates another heat map or thermal image of a fluid channel,such as the first fluid channel 36 illustrated in FIG. 3A, according toone embodiment similar to that portrayed in FIG. 7. Once again, a “dryout” region is similarly portrayed, as explained above. Thelighter-shaded regions illustrate an uneven heat exchange distribution,with heightened temperature being shown in a specific region of thefluid channel (e.g., toward the outlet manifold, and in the second andthird quadrant). This can negatively impact the performance of the heatexchanger 20 in general. This uneven, non-uniform heat transfer may becaused by the shape of the hybrid counter cross flow path nature of theheat exchanger 20 itself. For example, due to the rounded corners (e.g.,narrowed ends 25) and rounded shape of manifolds 40, 42, 44, 46 thatcome with the hybrid counter cross flow path design, the fluid channelslocated in the middle of the fluid passages 36, 38 are longer than thefluid channels located at the ends of the fluid passages 36, 38, asexplained above with reference to FIG. 4. This may lead tocharacteristics similar to the heat map shown in FIG. 9A in which thefluid in the “dry out” region is refrigerant in a gas form, and theremainder of the refrigerant in a liquid. This may cause a spike influid transfer abnormalities at the transition phase between liquid togas, along the line labeled in FIG. 9A.

FIG. 9B shows another embodiment of solving this “dry out” phenomena toimprove the performance of the heat exchanger 20. According to thisembodiment, an interior volume of the first inlet manifold 40 isreduced. This can restrict fluid flow and normalize or even-out the heatdistribution. To reduce the volume of the first inlet manifold 40, thefirst inlet manifold 40 can be shaped with a cut-out surface 110. Inother words, the exterior surface of the first inlet manifold 40 can beconcave or otherwise indented to reduce the interior volume. Inparticular, the interior volume of the first inlet manifold 40 can bereduced more toward the center of the first inlet manifold 40. Saidanother way, and referring to FIGS. 8A-8C, the interior of the outerwall 104 can be convex or otherwise protrude into the interior of themanifold 40 to create a smaller interior volume, while the interior ofthe outer wall 104 at the other manifolds 42-46 may be planar or concaveto create a larger interior volume. The same teachings can be applied tothe second inlet manifold 44, as the case may be. This restricts fluidflow in the miniature channels (defined between the fins 52 describedabove) that are toward the center of the first fluid channel 36 comparedto the miniature channels that are toward the perimeter of the firstfluid channel.

In other embodiments, the interior volume of the first inlet manifold 40is reduced in other fashions. For example, the thickness of the interiorof the first inlet manifold can remain consistent (like the othermanifolds 42, 44, 46), but thinner than the other manifolds. In anotherembodiment, all of the outer walls of the manifolds 40-46 are convex(e.g., concave from the interior perspective), but the outer walls ofthe other three manifolds 42, 44, 46 is more convex (or concave) thanthe first inlet manifold 40.

Once again, it should be understood that the teachings of FIG. 9B shouldnot be construed as to only applying to the first inlet manifold 40. Thereduction in volume of the other manifolds can also be performeddepending on the desired fluid flow characteristics.

FIG. 10 illustrates a top perspective cut-away view of one embodiment ofan interior of a fluid manifold of a heat exchanger. The illustratedfluid manifold can be any of the fluid manifolds described herein, butfor illustrated purposes, the fluid manifold is the second outletmanifold 46. The view shown is a cross-section view through one of thesecond fluid channels 38, namely at a location where the second fluidchannel 38 meets the second outlet manifold 46. Looking into the secondoutlet manifold 46, the location of the stacked, alternating first andsecond fluid channels 36, 38 are shown behind an interior side wall 118of the second outlet manifold 46.

In order to maximize contact area between hot and cold fluid passages ofthe heat exchanger 20, the second outlet manifold 46 is provided with aplurality of surface features 120 therein. The surface features 120 areformed via the same forming process (e.g., 3D printing) as the remainderof the main body 22 of the heat exchanger 20. The surface features 120can be extensions or protrusions formed to extend into the interiorvolume of the second outlet manifold 46.

The surface features 120 may include a plurality of fins 122. The fins122 may be projections or protrusions extending generally horizontalfrom the interior side wall 118 of the second outlet manifold 46. Inother embodiments, the fins 122 may be dimples, vanes, or otherprojections or protrusions that provide additional surface area contactbetween fluid in the second outlet manifold 46 and the material of themain body 22 of the heat exchanger 20.

The surface features 120 may also include ribs 124. The ribs 124 mayextend along the curved contour of the second outlet manifold 46, alongthe interior side wall 118 thereof. The ribs 124 may be generallylongitudinal, and may extend generally transverse or perpendicular tothe fins 122. In one embodiment, a pair of ribs 124 may extend on eithervertical side of a row of fins 122, as shown in FIG. 10.

The surface features 120 may also include enlarged projections 126extending into the second outlet manifold 46. The enlarged projections126 may be located between a pair of ribs 124 in which the fins 122 arenot located. In other words, going downward into the second outletmanifold 46, each layer of adjacent ribs 124 has, therebetween, aplurality of fins 122 or a plurality of enlarged projections 126, inalternating fashion.

In one embodiment, each rib 124 is horizontally aligned with one of theplates 60. In other words, each rib 124 is provided at a locationbetween opposing fluid channels (e.g., between one of the first fluidchannels 36 and one of the second fluid channels 38).

FIG. 11 illustrates a similar view as FIG. 10, removing some of the fins122 to highlight the enlarged projections 126. The enlarged projections126 may also be referred to as structural bridges 126. The interior sidewall 118 may be relatively thin to enable a proper, efficient heattransfer between the opposing first and second fluids. To better supportthe interior side wall 118, the structural bridges 126 may extendoutwardly therefrom. Each structural bridge 126 may be tapered orotherwise sloped to enlarge downwardly. The structural bridges 126,while in the second outlet manifold 46, may be aligned with the firstchannels 36 such that they are aligned with the first fluid that doesnot enter the second outlet manifold 46. This allows the structuralbridges 126 to not only structurally support the interior side wall 118,but also provide added heat transfer benefits to the heat exchanger 20by increasing the surface area of heat exchange between the first fluidand the second fluid.

FIG. 12 illustrates a top plan view of the heat exchanger 20,highlighting an upper surface 130 of the main body 22. The first fluidinlet 26 and first fluid outlet 28 are also visible, as is the secondfluid inlet 30 and second fluid outlet 32 that are each in fluidcommunication with a respective fluid manifold, as described above.

An upper surface 132 of the jumper pipe 62 is also illustrated. Asexplained above, the jumper pipe 62 transports fluid from the firstfluid inlet 26 into the first inlet manifold 40. This flow directionwithin the jumper pipe 62 is illustrated with arrow 134, which islinear. As can be seen in FIG. 12 as well as FIG. 13 (which is across-sectional view taken along line B-B of FIG. 12), by having thejumper pipe 62 integrated into the heat exchanger 20 (e.g., via 3Dprinting), this can create sharp angles at the intersection of thejumper pipe 62 and the first fluid manifold 40. The material that makesup the upper surface 130 of the main body 22 has the potential to berelatively weak at certain locations, for example locations 136 and 138labeled in FIG. 13 at the intersection of the jumper pipe 62 and thefirst fluid manifold 40. If 3D printing is utilized for manufacturing,during the printing process, the sharp angles create the potential forthe printer recoater to interact with the part itself, which can cause atear or leak.

FIG. 14 illustrates another embodiment of with a redesigned jumper pipeto reduce the presence of such sharp angles. In this embodiment, theheat exchanger 20′ has an upper surface 130′ defining a jumper pipe 62′having a curved shape, indicated by arrow 134′. This creates angles ofintersection between the jumper pipe 62′ and the first inlet manifold40′ that have more favorable angles for 3D printing.

The jumper pipe 62′ may be J-shaped. In one embodiment, the jumper pipe62 includes a first end 140 adjacent to the first fluid inlet, and asecond end 142 adjacent to the first inlet manifold 40′. The jumper pipecan extend linearly at the first end 140, and curved at the second end142. In other words, the jumper pipe 62′ can include a linear section(e.g., closer to the first end 140) and a curved section (e.g., closerto the second end 142). The curve at the second end 142 can be such thatthe second end 142 is directed to intersect the first inlet manifold 40′at more of a perpendicular angle relative to the direction shown in FIG.12. The angle of intersection between the second end 142 of the jumperpipe 62′ and the first inlet manifold 40′ may be generally perpendicular(e.g., between 80 and 100 degrees, or more particularly between 85 and95 degrees). In another embodiment, the jumper pipe 62′ may be S-shapedsuch that both the first end 140 and the second end 142 are curved, andthe flow path 134′ does not have a significant portion that is linear.

FIGS. 15A and 15B collectively illustrate another embodiment of anoverall shape of a heat exchanger 150. The shape of the heat exchanger150 is shown in FIG. 15B. To help visualize this shape, FIG. 15Aillustrates a top schematic plan view of the first fluid channel 36 ofthe heat exchanger described with reference to FIG. 3A, with a twistarrow 152. This twist arrow 152 indicates a direction in which the shapeof the heat exchanger can be “twisted” to create the new shape of theheat exchanger 150 shown in FIG. 15B. The heat exchanger 150 can bemanufactured to this shape with the above-disclosed manufacturingmethods (e.g., 3D printing). The “twisting” can be performed along alongitudinal axis of the heat exchanger 20. Essentially, one end (e.g.,to the left in FIGS. 15A-15B) can be maintained stationary, and theother end (e.g., to the right in FIGS. 15A-15B) can be twisted aroundthis axis. This can create the desired shape shown in FIG. 15B.

The addition of a twist in the central section of the heat exchanger canelongate the miniature channels within the first fluid channel 36, forexample. With the twisted design, the miniature channels furthest fromthe central twist axis can increase in length, while the miniaturechannels closest to the axis will not. This can create a heat exchanger150 with uniform channel lengths (e.g., the plotted line in FIG. 4 wouldbe straight and horizontal), which can normalize the heat transferprocess.

The words used in this specification are words of description ratherthan limitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the disclosure. Aspreviously described, the features of various embodiments may becombined to form further embodiments that may not be explicitlydescribed or illustrated. While various embodiments could have beendescribed as providing advantages or being preferred over otherembodiments or prior art implementations with respect to one or moredesired characteristics, those of ordinary skill in the art recognizethat one or more features or characteristics may be compromised toachieve desired overall system attributes, which depend on the specificapplication and implementation. As such, embodiments described as lessdesirable than other embodiments or prior art implementations withrespect to one or more characteristics are not outside the scope of thedisclosure and may be desirable for particular applications.

What is claimed is:
 1. A heat exchanger comprising: a main body defininga first fluid inlet port, a first fluid outlet port, a second fluidinlet port, and a second fluid outlet port, wherein each of the firstand second fluid inlet ports and first and second fluid outlet ports areintegrally formed with the main body; a plurality of plates in a stackedarrangement and integrally formed with the main body; a plurality offirst fluid channels defined by the main body and in fluid communicationwith the first fluid inlet port to receive a first fluid therefrom; anda plurality of second fluid channels defined by the main body and influid communication with the second fluid inlet port to receive a secondfluid therefrom; wherein the first fluid channels and the second fluidchannels are interposed between the plates in alternating fashion alongthe stacked arrangement.
 2. The heat exchanger of claim 1, wherein themain body and the plurality of plates are 3D printed as part of asingle, unitary piece.
 3. The heat exchanger of claim 2, wherein thefirst fluid channels and the second fluid channels are defined by gapsbetween the plurality of plates such that fluid flowing in the first andsecond fluid channels directly contacts the plates.
 4. The heatexchanger of claim 1, wherein the main body further defines a firstinlet manifold and a first outlet manifold in fluid communication withthe first fluid channels, and wherein the main body further defines asecond inlet manifold and a second outlet manifold in fluidcommunication with the second fluid channels, wherein each of the firstand second inlet manifolds and first and second outlet manifolds areintegrally formed with the main body.
 5. The heat exchanger of claim 4,wherein the first inlet manifold and first outlet manifold are onopposite sides of the heat exchanger, and the first fluid inlet port andthe second fluid inlet port are directly adjacent one another.
 6. Theheat exchanger of claim 5, further comprising a jumper pipe fluidlyconnecting the first fluid inlet port to the first inlet manifold,wherein the jumper pipe extends across an upper-most plate of pluralityof plates and is integrally formed with the main body.
 7. The heatexchanger of claim 5, wherein the first fluid inlet port and the firstfluid outlet port are integrally formed as part of a common extrusionand configured to connect to a single fluid coupling.
 8. The heatexchanger of claim 1, wherein the first fluid channels and the secondfluid channels each have a plurality of fins extending therein, whereinthe fins are integrally formed with the main body and are configured todirectly fluid flow within the first and second fluid channels.
 9. Theheat exchanger of claim 1, wherein first fluid channels and the secondfluid channels are arranged such that (i) the first fluid flows in adirection opposite to the second fluid in a central region of the firstand second fluid channels, and (ii) the first fluid flows in a directiontransverse to the second fluid in an outer region of the first andsecond fluid channels.
 10. A heat exchanger comprising: a main bodydefining a first fluid inlet port, a first fluid outlet port, a secondfluid inlet port, and a second fluid outlet port, wherein each of thefirst and second fluid inlet ports and first and second fluid outletports are integrally formed with the main body; a plurality of plates ina stacked arrangement and integrally formed with the main body, theplurality of plates defining fluid channels therebetween, the pluralityof plates including an upper-most plate; and a plurality of manifoldsintegrally formed with the main body, the plurality of manifoldsincluding: a first inlet manifold configured to receive a first fluidfrom the first fluid inlet port, a first outlet manifold configured tosend the first fluid to the first fluid outlet port, wherein the firstoutlet manifold is located on an opposite side of the heat exchangerfrom the first inlet manifold, a second inlet manifold configured toreceive a second fluid from the second fluid inlet port, and a secondoutlet manifold configured to send the second fluid to the second fluidoutlet port, wherein the second outlet manifold is located on anopposite side of the heat exchanger from the second inlet manifold; anda jumper pipe integrally formed with the main body, wherein the jumperpipe extends across the upper-most plate and transfers the first fluidfrom the first fluid inlet port to the first inlet manifold.
 11. Theheat exchanger of claim 10, wherein the first fluid inlet port and thefirst fluid outlet port are integrally formed as part of a commonextrusion and are configured to connect to a single fluid coupling. 12.The heat exchanger of claim 11, wherein the second fluid inlet port islocated on an opposite side of the heat exchanger relative to the secondfluid outlet port.
 13. The heat exchanger of claim 11, wherein the fluidchannels include an upper-most fluid channel, and the upper-most plateis located directly between and defines boundaries of the jumper pipeand the upper-most fluid channel.
 14. The heat exchanger of claim 13,wherein the upper-most plate is entirely solid.
 15. The heat exchangerof claim 13, wherein the upper-most plate includes a void or gap definedtherein configured to thermally insulate the jumper pipe from theupper-most fluid channel.
 16. The heat exchanger of claim 15, whereinthe void or gap is fluidly coupled to a powder-evacuation holeconfigured to be exposed to atmosphere.
 17. A 3D-printed chiller heatexchanger comprising: a main body of a single continuous solid materialdefining: a plurality of plates arranged in a stack and formed as partof a single unitary body, a plurality of first fluid channels and aplurality of second fluid channels interposed between the plates inalternating fashion such that each of the first fluid channels isdirectly adjacent to a respective one of the second fluid channels andseparated by a respective one of the plates, a first inlet manifold anda first outlet manifold in fluid communication with the plurality offirst fluid channels, a second inlet manifold and a second outletmanifold in fluid communication with the plurality of second fluidchannels, a first fluid inlet port and a first fluid outlet portconfigured to allow a first fluid to enter and exit the heat exchanger,the first fluid inlet port and first fluid outlet port in fluidcommunication with the first fluid channels, a second fluid inlet portand a second fluid outlet port configured to allow a second fluid toenter and exit the heat exchanger, the second fluid inlet port andsecond fluid outlet port in fluid communication with the second fluidchannels, and a jumper pipe fluidly connecting the first fluid inletport to the first inlet manifold.
 18. The 3D-printed chiller heatexchanger of claim 17, wherein the jumper pipe extends across anupper-most plate of the plurality of plates.
 19. The 3D-printed chillerheat exchanger of claim 18, wherein the main body further defines a gapor void located vertically between the jumper pipe and the plurality offirst fluid channels to provide thermal insulation therebetween.
 20. The3D-printed chiller heat exchanger of claim 18, wherein the upper-mostplate is located directly between and defines boundaries of the jumperpipe and an upper-most fluid channel of the first and second fluidchannels, and wherein the upper plate includes no gap or void therein.